This invention relates to signal detecting arrangements and, more particularly, to methods and arrangements for detecting speech activity in the presence of noise.
Speech detection arrangements are useful in a variety of speech transmission systems in which speech transmission paths are established in response to the detection of speech activity, such as for speech interpolation or echo suppression break-in purposes. Ideally, a speech detector should be highly sensitive to the presence of speech signals while at the same time remaining insensitive to non-speech signals, which typically include various types of noise present in the transmission system environment. The difficulty has been in distinguishing quickly and accurately between speech, particularly low level speech, and certain of the noise signals. Consequently, known methods and arrangements for detecting speech have generally suffered from such limitations as undesirable speech clipping on the one hand and excessive system activity due to noise sensitivity on the other hand.